1. Industrial Applicable Field
The invention relates to a method for producing an axial asymmetric aminophosphine compound, an intermediate for producing the same, a method for producing a complex of a metal such as ruthenium, rhodium, iridium or nickel and the compound, and a catalyst for asymmetric hydrogenation or carbon-carbon bond formation using the complex.
2. Related Art Statement
There has been a number of reports describing complexes of transition metal elements available for asymmetric synthesis such as asymmetric hydrogenation, asymmetric isomerization or asymmetric hydrosilylation. Particularly, a complex of a transition metal element, such as ruthenium, rhodium, iridium, palladium or the like, with an optically active tertiary phosphine compound as its ligand has excellent properties as a catalyst for asymmetric synthesis.
Phosphine compounds with various chemical structures have been developed for further improving their performances as the catalysts ("Chemical Review" 32, "chemistry of organic metal complexes", page 237 to 238, edited by Japan Chemical Society, 1982) ("Asymmetric Catalysis in Organic Synthesis" Noyori Yoshiharu, A Wiley-Interscience Publication). 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (referred to as "BINAP" below) is one of optically active phosphines having excellent properties. A complex of rhodium with "BINAP" is described in Japanese Patent Laid-Open publication "Kokai" 61973/1980 and a complex of ruthenium with "BINAP" is described in Japanese Patent Laid-Open publication "Kokai" 6390/1986. Further, a complex having 2,2'-bis[di(p-tolyl)phosphino]-1,1'-binapthyl (referred to as "p-Tol-BINAP" below) as its ligand is described in Japanese Patent Laid-Open publication "Kokai" 199898/1985 (rhodium) or 63690/1986 (ruthenium). These complexes are reported to provide good results for asymmetric hydrogenation and asymmetric isomerization. Further, Japanese Patent Laid-Open publication "Kokai" 255090/1991 discloses ruthenium complex of 2,2'-bis(di-3,5-dialkylphenyl)phosphino)-1,1 '-binapthyl to have superior performance as a catalyst for asymmetric hydrogenation of .beta.-ketoesters.
Further, palladium complexes of aminophosphine compounds have been used for asymmetric hydrosilylation. For example, a palladium complex having as its ligand an optically active aminophosphine compound with ferrocene bone structure is effective as a catalyst for asymmetric hydrosilylation of a conjugated diene compound with trichlorosilane (Tetrahedron Lett., Asymmetry, 1, 151(1990)). A palladium complex having an aminophosphine compound with N-sulfonyl group as its ligand is effective as a catalyst for hydrosilylation of styrene with chlorosilane (Chem. Lett. 999(1990)). Further, a nickel complex having as its ligand an aminophosphine compound having ferrocene bone structure is effective as a catalyst for asymmetric cross-coupling reaction of 1-phenylethylmagnesium chloride and vinyl chloride (J. Am. Chem. Soc. 104, 180(1982)). However, the above catalysts do not necessarily have sufficient chemical selectivity, enantioselectivity and catalytic activity depending on the reaction type or the substrate, leading to the needs for improving these kinds of catalysts.
Further, a phosphine compound 7 having a nitrogen atom in its molecule has been synthesized using an optically active 2-amino-2'-hydroxybinaphthyl as a starting material, according to the method described in a publication (J. Org. Chem. 63, 7738 (1988)). Moreover, an optically active 2-amino-2'-hydroxybinaphthyl has been obtained by the oxidative addition of 2-aminonaphthalene and 2-hydroxynaphthalene in the presence of sparteine or phenethylamine, or by the optical resolution of racemic mixture of 2-amino-2'-hydroxybinaphthyl. However, 2-aminonaphthalene is now difficult to obtain in the market due to its carcinogenicity and the above synthetic route using it is not desirable in the viewpoint of environmental protection. ##STR2##
The inventive process utilizes safe 1,1'-bi-2-naphthol as the starting material for synthesizing a ligand composed of a phosphine having a nitrogen atom within its molecule, thus avoiding the above problems. Further, according to the examples in the above publication, as shown in the following scheme 1, the compound 8 is subjected to a substitution reaction of its allyl position with malonic ester in the presence of a catalyst containing palladium (so called "Tsuji reaction"). ##STR3##
All the examples in the above publication is performed according to the above reaction scheme. Moreover, all the ligands used in the examples are selected from the following phosphine compounds 11, 12, 13 and 14, each having a dialkylamino group. The following free aminophosphine 15 is used only as a starting material and not used as a ligand throughout the examples. ##STR4##